Mercurial > octave-nkf
view libinterp/corefcn/find.cc @ 17787:175b392e91fe
Use GNU style coding conventions for code in libinterp/
* libinterp/corefcn/Cell.h, libinterp/corefcn/__contourc__.cc,
libinterp/corefcn/__dispatch__.cc, libinterp/corefcn/__lin_interpn__.cc,
libinterp/corefcn/__pchip_deriv__.cc, libinterp/corefcn/__qp__.cc,
libinterp/corefcn/balance.cc, libinterp/corefcn/besselj.cc,
libinterp/corefcn/betainc.cc, libinterp/corefcn/bitfcns.cc,
libinterp/corefcn/bsxfun.cc, libinterp/corefcn/c-file-ptr-stream.cc,
libinterp/corefcn/c-file-ptr-stream.h, libinterp/corefcn/cellfun.cc,
libinterp/corefcn/colloc.cc, libinterp/corefcn/comment-list.h,
libinterp/corefcn/conv2.cc, libinterp/corefcn/daspk.cc,
libinterp/corefcn/dasrt.cc, libinterp/corefcn/dassl.cc,
libinterp/corefcn/data.cc, libinterp/corefcn/debug.cc,
libinterp/corefcn/defaults.cc, libinterp/corefcn/defaults.in.h,
libinterp/corefcn/defun-int.h, libinterp/corefcn/defun.cc,
libinterp/corefcn/det.cc, libinterp/corefcn/dirfns.cc,
libinterp/corefcn/display.cc, libinterp/corefcn/dlmread.cc,
libinterp/corefcn/dot.cc, libinterp/corefcn/dynamic-ld.cc,
libinterp/corefcn/dynamic-ld.h, libinterp/corefcn/eig.cc,
libinterp/corefcn/ellipj.cc, libinterp/corefcn/error.cc,
libinterp/corefcn/error.h, libinterp/corefcn/event-queue.h,
libinterp/corefcn/fft.cc, libinterp/corefcn/fft2.cc, libinterp/corefcn/fftn.cc,
libinterp/corefcn/file-io.cc, libinterp/corefcn/filter.cc,
libinterp/corefcn/find.cc, libinterp/corefcn/gammainc.cc,
libinterp/corefcn/gcd.cc, libinterp/corefcn/getgrent.cc,
libinterp/corefcn/getpwent.cc, libinterp/corefcn/getrusage.cc,
libinterp/corefcn/givens.cc, libinterp/corefcn/gl-render.cc,
libinterp/corefcn/gl2ps-renderer.cc, libinterp/corefcn/gl2ps-renderer.h,
libinterp/corefcn/graphics.cc, libinterp/corefcn/graphics.in.h,
libinterp/corefcn/gripes.cc, libinterp/corefcn/gripes.h,
libinterp/corefcn/help.cc, libinterp/corefcn/hess.cc,
libinterp/corefcn/hex2num.cc, libinterp/corefcn/input.cc,
libinterp/corefcn/input.h, libinterp/corefcn/inv.cc,
libinterp/corefcn/jit-ir.h, libinterp/corefcn/jit-typeinfo.cc,
libinterp/corefcn/jit-typeinfo.h, libinterp/corefcn/jit-util.h,
libinterp/corefcn/kron.cc, libinterp/corefcn/load-path.cc,
libinterp/corefcn/load-path.h, libinterp/corefcn/load-save.cc,
libinterp/corefcn/load-save.h, libinterp/corefcn/lookup.cc,
libinterp/corefcn/ls-ascii-helper.cc, libinterp/corefcn/ls-hdf5.cc,
libinterp/corefcn/ls-hdf5.h, libinterp/corefcn/ls-mat-ascii.cc,
libinterp/corefcn/ls-mat-ascii.h, libinterp/corefcn/ls-mat4.cc,
libinterp/corefcn/ls-mat5.cc, libinterp/corefcn/ls-mat5.h,
libinterp/corefcn/ls-oct-ascii.cc, libinterp/corefcn/lsode.cc,
libinterp/corefcn/lu.cc, libinterp/corefcn/luinc.cc,
libinterp/corefcn/mappers.cc, libinterp/corefcn/matrix_type.cc,
libinterp/corefcn/max.cc, libinterp/corefcn/md5sum.cc,
libinterp/corefcn/mex.cc, libinterp/corefcn/mexproto.h,
libinterp/corefcn/mgorth.cc, libinterp/corefcn/mxarray.in.h,
libinterp/corefcn/nproc.cc, libinterp/corefcn/oct-hist.cc,
libinterp/corefcn/oct-lvalue.h, libinterp/corefcn/oct-map.cc,
libinterp/corefcn/oct-map.h, libinterp/corefcn/oct-obj.h,
libinterp/corefcn/oct-prcstrm.h, libinterp/corefcn/oct-stdstrm.h,
libinterp/corefcn/oct-stream.cc, libinterp/corefcn/oct-stream.h,
libinterp/corefcn/octave-link.cc, libinterp/corefcn/octave-link.h,
libinterp/corefcn/pager.cc, libinterp/corefcn/pinv.cc,
libinterp/corefcn/pr-output.cc, libinterp/corefcn/procstream.h,
libinterp/corefcn/profiler.cc, libinterp/corefcn/pt-jit.cc,
libinterp/corefcn/pt-jit.h, libinterp/corefcn/quad.cc,
libinterp/corefcn/quadcc.cc, libinterp/corefcn/qz.cc,
libinterp/corefcn/rand.cc, libinterp/corefcn/rcond.cc,
libinterp/corefcn/regexp.cc, libinterp/corefcn/schur.cc,
libinterp/corefcn/sighandlers.cc, libinterp/corefcn/sighandlers.h,
libinterp/corefcn/sparse-xdiv.cc, libinterp/corefcn/sparse-xdiv.h,
libinterp/corefcn/sparse-xpow.cc, libinterp/corefcn/sparse.cc,
libinterp/corefcn/spparms.cc, libinterp/corefcn/sqrtm.cc,
libinterp/corefcn/str2double.cc, libinterp/corefcn/strfind.cc,
libinterp/corefcn/strfns.cc, libinterp/corefcn/sub2ind.cc,
libinterp/corefcn/svd.cc, libinterp/corefcn/syl.cc,
libinterp/corefcn/symtab.cc, libinterp/corefcn/symtab.h,
libinterp/corefcn/syscalls.cc, libinterp/corefcn/sysdep.cc,
libinterp/corefcn/sysdep.h, libinterp/corefcn/time.cc,
libinterp/corefcn/toplev.cc, libinterp/corefcn/toplev.h,
libinterp/corefcn/tril.cc, libinterp/corefcn/txt-eng-ft.cc,
libinterp/corefcn/txt-eng-ft.h, libinterp/corefcn/txt-eng.h,
libinterp/corefcn/typecast.cc, libinterp/corefcn/urlwrite.cc,
libinterp/corefcn/utils.cc, libinterp/corefcn/variables.cc,
libinterp/corefcn/variables.h, libinterp/corefcn/xdiv.cc,
libinterp/corefcn/xdiv.h, libinterp/corefcn/xnorm.h, libinterp/corefcn/xpow.cc,
libinterp/corefcn/xpow.h, libinterp/corefcn/zfstream.cc,
libinterp/corefcn/zfstream.h, libinterp/dldfcn/__delaunayn__.cc,
libinterp/dldfcn/__dsearchn__.cc, libinterp/dldfcn/__eigs__.cc,
libinterp/dldfcn/__fltk_uigetfile__.cc, libinterp/dldfcn/__glpk__.cc,
libinterp/dldfcn/__init_fltk__.cc, libinterp/dldfcn/__init_gnuplot__.cc,
libinterp/dldfcn/__magick_read__.cc, libinterp/dldfcn/__voronoi__.cc,
libinterp/dldfcn/amd.cc, libinterp/dldfcn/ccolamd.cc, libinterp/dldfcn/chol.cc,
libinterp/dldfcn/colamd.cc, libinterp/dldfcn/convhulln.cc,
libinterp/dldfcn/dmperm.cc, libinterp/dldfcn/fftw.cc, libinterp/dldfcn/qr.cc,
libinterp/dldfcn/symbfact.cc, libinterp/dldfcn/symrcm.cc,
libinterp/dldfcn/tsearch.cc, libinterp/octave-value/ov-base-diag.cc,
libinterp/octave-value/ov-base-diag.h, libinterp/octave-value/ov-base-int.cc,
libinterp/octave-value/ov-base-int.h, libinterp/octave-value/ov-base-mat.h,
libinterp/octave-value/ov-base-scalar.cc,
libinterp/octave-value/ov-base-scalar.h,
libinterp/octave-value/ov-base-sparse.cc,
libinterp/octave-value/ov-base-sparse.h, libinterp/octave-value/ov-base.cc,
libinterp/octave-value/ov-base.h, libinterp/octave-value/ov-bool-mat.cc,
libinterp/octave-value/ov-bool-mat.h, libinterp/octave-value/ov-bool-sparse.cc,
libinterp/octave-value/ov-bool-sparse.h, libinterp/octave-value/ov-bool.cc,
libinterp/octave-value/ov-bool.h, libinterp/octave-value/ov-builtin.cc,
libinterp/octave-value/ov-builtin.h, libinterp/octave-value/ov-cell.cc,
libinterp/octave-value/ov-cell.h, libinterp/octave-value/ov-ch-mat.cc,
libinterp/octave-value/ov-ch-mat.h, libinterp/octave-value/ov-class.cc,
libinterp/octave-value/ov-class.h, libinterp/octave-value/ov-colon.h,
libinterp/octave-value/ov-complex.cc, libinterp/octave-value/ov-complex.h,
libinterp/octave-value/ov-cx-diag.cc, libinterp/octave-value/ov-cx-diag.h,
libinterp/octave-value/ov-cx-mat.cc, libinterp/octave-value/ov-cx-mat.h,
libinterp/octave-value/ov-cx-sparse.cc, libinterp/octave-value/ov-cx-sparse.h,
libinterp/octave-value/ov-dld-fcn.h, libinterp/octave-value/ov-fcn-handle.cc,
libinterp/octave-value/ov-fcn-handle.h,
libinterp/octave-value/ov-fcn-inline.cc,
libinterp/octave-value/ov-fcn-inline.h, libinterp/octave-value/ov-fcn.h,
libinterp/octave-value/ov-float.cc, libinterp/octave-value/ov-float.h,
libinterp/octave-value/ov-flt-complex.cc,
libinterp/octave-value/ov-flt-complex.h,
libinterp/octave-value/ov-flt-cx-diag.cc,
libinterp/octave-value/ov-flt-cx-diag.h,
libinterp/octave-value/ov-flt-cx-mat.cc,
libinterp/octave-value/ov-flt-cx-mat.h,
libinterp/octave-value/ov-flt-re-diag.cc,
libinterp/octave-value/ov-flt-re-diag.h,
libinterp/octave-value/ov-flt-re-mat.cc,
libinterp/octave-value/ov-flt-re-mat.h, libinterp/octave-value/ov-int16.cc,
libinterp/octave-value/ov-int32.cc, libinterp/octave-value/ov-int64.cc,
libinterp/octave-value/ov-int8.cc, libinterp/octave-value/ov-intx.h,
libinterp/octave-value/ov-java.cc, libinterp/octave-value/ov-lazy-idx.h,
libinterp/octave-value/ov-mex-fcn.cc, libinterp/octave-value/ov-mex-fcn.h,
libinterp/octave-value/ov-null-mat.cc, libinterp/octave-value/ov-null-mat.h,
libinterp/octave-value/ov-oncleanup.cc, libinterp/octave-value/ov-perm.cc,
libinterp/octave-value/ov-perm.h, libinterp/octave-value/ov-range.cc,
libinterp/octave-value/ov-range.h, libinterp/octave-value/ov-re-diag.cc,
libinterp/octave-value/ov-re-diag.h, libinterp/octave-value/ov-re-mat.cc,
libinterp/octave-value/ov-re-mat.h, libinterp/octave-value/ov-re-sparse.cc,
libinterp/octave-value/ov-re-sparse.h, libinterp/octave-value/ov-scalar.cc,
libinterp/octave-value/ov-scalar.h, libinterp/octave-value/ov-str-mat.cc,
libinterp/octave-value/ov-str-mat.h, libinterp/octave-value/ov-struct.cc,
libinterp/octave-value/ov-struct.h, libinterp/octave-value/ov-type-conv.h,
libinterp/octave-value/ov-typeinfo.cc, libinterp/octave-value/ov-typeinfo.h,
libinterp/octave-value/ov-uint16.cc, libinterp/octave-value/ov-uint32.cc,
libinterp/octave-value/ov-uint64.cc, libinterp/octave-value/ov-uint8.cc,
libinterp/octave-value/ov-usr-fcn.cc, libinterp/octave-value/ov-usr-fcn.h,
libinterp/octave-value/ov.cc, libinterp/octave-value/ov.h, libinterp/octave.cc,
libinterp/operators/op-b-bm.cc, libinterp/operators/op-b-sbm.cc,
libinterp/operators/op-bm-b.cc, libinterp/operators/op-bm-bm.cc,
libinterp/operators/op-cdm-cdm.cc, libinterp/operators/op-chm.cc,
libinterp/operators/op-class.cc, libinterp/operators/op-cm-cm.cc,
libinterp/operators/op-cm-cs.cc, libinterp/operators/op-cm-s.cc,
libinterp/operators/op-cm-scm.cc, libinterp/operators/op-cm-sm.cc,
libinterp/operators/op-cs-cm.cc, libinterp/operators/op-cs-cs.cc,
libinterp/operators/op-cs-scm.cc, libinterp/operators/op-cs-sm.cc,
libinterp/operators/op-dm-dm.cc, libinterp/operators/op-dm-scm.cc,
libinterp/operators/op-double-conv.cc, libinterp/operators/op-fcdm-fcdm.cc,
libinterp/operators/op-fcm-fcm.cc, libinterp/operators/op-fcm-fcs.cc,
libinterp/operators/op-fcm-fm.cc, libinterp/operators/op-fcm-fs.cc,
libinterp/operators/op-fcs-fcm.cc, libinterp/operators/op-fcs-fcs.cc,
libinterp/operators/op-fcs-fm.cc, libinterp/operators/op-fcs-fs.cc,
libinterp/operators/op-fdm-fdm.cc, libinterp/operators/op-float-conv.cc,
libinterp/operators/op-fm-fcm.cc, libinterp/operators/op-fm-fcs.cc,
libinterp/operators/op-fm-fm.cc, libinterp/operators/op-fm-fs.cc,
libinterp/operators/op-fs-fcm.cc, libinterp/operators/op-fs-fcs.cc,
libinterp/operators/op-fs-fm.cc, libinterp/operators/op-fs-fs.cc,
libinterp/operators/op-m-cm.cc, libinterp/operators/op-m-cs.cc,
libinterp/operators/op-m-m.cc, libinterp/operators/op-m-s.cc,
libinterp/operators/op-m-scm.cc, libinterp/operators/op-m-sm.cc,
libinterp/operators/op-pm-scm.cc, libinterp/operators/op-range.cc,
libinterp/operators/op-s-cm.cc, libinterp/operators/op-s-cs.cc,
libinterp/operators/op-s-scm.cc, libinterp/operators/op-sbm-b.cc,
libinterp/operators/op-sbm-bm.cc, libinterp/operators/op-sbm-sbm.cc,
libinterp/operators/op-scm-cm.cc, libinterp/operators/op-scm-cs.cc,
libinterp/operators/op-scm-m.cc, libinterp/operators/op-scm-s.cc,
libinterp/operators/op-scm-scm.cc, libinterp/operators/op-scm-sm.cc,
libinterp/operators/op-sm-cm.cc, libinterp/operators/op-sm-m.cc,
libinterp/operators/op-sm-s.cc, libinterp/operators/op-sm-scm.cc,
libinterp/operators/op-sm-sm.cc, libinterp/operators/op-str-m.cc,
libinterp/operators/op-str-s.cc, libinterp/operators/op-str-str.cc,
libinterp/operators/ops.h, libinterp/parse-tree/lex.h,
libinterp/parse-tree/parse.h, libinterp/parse-tree/pt-arg-list.cc,
libinterp/parse-tree/pt-arg-list.h, libinterp/parse-tree/pt-assign.cc,
libinterp/parse-tree/pt-assign.h, libinterp/parse-tree/pt-binop.cc,
libinterp/parse-tree/pt-binop.h, libinterp/parse-tree/pt-bp.h,
libinterp/parse-tree/pt-cbinop.cc, libinterp/parse-tree/pt-check.cc,
libinterp/parse-tree/pt-colon.cc, libinterp/parse-tree/pt-colon.h,
libinterp/parse-tree/pt-const.cc, libinterp/parse-tree/pt-decl.cc,
libinterp/parse-tree/pt-decl.h, libinterp/parse-tree/pt-eval.cc,
libinterp/parse-tree/pt-except.h, libinterp/parse-tree/pt-exp.h,
libinterp/parse-tree/pt-fcn-handle.cc, libinterp/parse-tree/pt-id.cc,
libinterp/parse-tree/pt-id.h, libinterp/parse-tree/pt-idx.cc,
libinterp/parse-tree/pt-idx.h, libinterp/parse-tree/pt-loop.h,
libinterp/parse-tree/pt-mat.cc, libinterp/parse-tree/pt-misc.cc,
libinterp/parse-tree/pt-misc.h, libinterp/parse-tree/pt-pr-code.cc,
libinterp/parse-tree/pt-select.h, libinterp/parse-tree/pt-stmt.h,
libinterp/parse-tree/token.h, libinterp/version.cc:
Use GNU style coding conventions for code in libinterp/
author | Rik <rik@octave.org> |
---|---|
date | Mon, 28 Oct 2013 19:51:46 -0700 |
parents | d63878346099 |
children | 6a71e5030df5 a5286fb173cd |
line wrap: on
line source
/* Copyright (C) 1996-2013 John W. Eaton This file is part of Octave. Octave is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. Octave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Octave; see the file COPYING. If not, see <http://www.gnu.org/licenses/>. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "quit.h" #include "defun.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" // Find at most N_TO_FIND nonzero elements in NDA. Search forward if // DIRECTION is 1, backward if it is -1. NARGOUT is the number of // output arguments. If N_TO_FIND is -1, find all nonzero elements. template <typename T> octave_value_list find_nonzero_elem_idx (const Array<T>& nda, int nargout, octave_idx_type n_to_find, int direction) { octave_value_list retval ((nargout == 0 ? 1 : nargout), Matrix ()); Array<octave_idx_type> idx; if (n_to_find >= 0) idx = nda.find (n_to_find, direction == -1); else idx = nda.find (); // The maximum element is always at the end. octave_idx_type iext = idx.is_empty () ? 0 : idx.xelem (idx.numel () - 1) + 1; switch (nargout) { default: case 3: retval(2) = Array<T> (nda.index (idx_vector (idx))); // Fall through! case 2: { Array<octave_idx_type> jdx (idx.dims ()); octave_idx_type n = idx.length (), nr = nda.rows (); for (octave_idx_type i = 0; i < n; i++) { jdx.xelem (i) = idx.xelem (i) / nr; idx.xelem (i) %= nr; } iext = -1; retval(1) = idx_vector (jdx, -1); } // Fall through! case 1: case 0: retval(0) = idx_vector (idx, iext); break; } return retval; } template <typename T> octave_value_list find_nonzero_elem_idx (const Sparse<T>& v, int nargout, octave_idx_type n_to_find, int direction) { octave_value_list retval ((nargout == 0 ? 1 : nargout), Matrix ()); octave_idx_type nc = v.cols (); octave_idx_type nr = v.rows (); octave_idx_type nz = v.nnz (); // Search in the default range. octave_idx_type start_nc = -1; octave_idx_type end_nc = -1; octave_idx_type count; // Search for the range to search if (n_to_find < 0) { start_nc = 0; end_nc = nc; n_to_find = nz; count = nz; } else if (direction > 0) { for (octave_idx_type j = 0; j < nc; j++) { OCTAVE_QUIT; if (v.cidx (j) == 0 && v.cidx (j+1) != 0) start_nc = j; if (v.cidx (j+1) >= n_to_find) { end_nc = j + 1; break; } } } else { for (octave_idx_type j = nc; j > 0; j--) { OCTAVE_QUIT; if (v.cidx (j) == nz && v.cidx (j-1) != nz) end_nc = j; if (nz - v.cidx (j-1) >= n_to_find) { start_nc = j - 1; break; } } } count = (n_to_find > v.cidx (end_nc) - v.cidx (start_nc) ? v.cidx (end_nc) - v.cidx (start_nc) : n_to_find); // If the original argument was a row vector, force a row vector of // the overall indices to be returned. But see below for scalar // case... octave_idx_type result_nr = count; octave_idx_type result_nc = 1; bool scalar_arg = false; if (v.rows () == 1) { result_nr = 1; result_nc = count; scalar_arg = (v.columns () == 1); } Matrix idx (result_nr, result_nc); Matrix i_idx (result_nr, result_nc); Matrix j_idx (result_nr, result_nc); Array<T> val (dim_vector (result_nr, result_nc)); if (count > 0) { // Search for elements to return. Only search the region where // there are elements to be found using the count that we want // to find. for (octave_idx_type j = start_nc, cx = 0; j < end_nc; j++) for (octave_idx_type i = v.cidx (j); i < v.cidx (j+1); i++ ) { OCTAVE_QUIT; if (direction < 0 && i < nz - count) continue; i_idx(cx) = static_cast<double> (v.ridx (i) + 1); j_idx(cx) = static_cast<double> (j + 1); idx(cx) = j * nr + v.ridx (i) + 1; val(cx) = v.data(i); cx++; if (cx == count) break; } } else if (scalar_arg) { idx.resize (0, 0); i_idx.resize (0, 0); j_idx.resize (0, 0); val.resize (dim_vector (0, 0)); } switch (nargout) { case 0: case 1: retval(0) = idx; break; case 5: retval(4) = nc; // Fall through case 4: retval(3) = nr; // Fall through case 3: retval(2) = val; // Fall through! case 2: retval(1) = j_idx; retval(0) = i_idx; break; default: panic_impossible (); break; } return retval; } octave_value_list find_nonzero_elem_idx (const PermMatrix& v, int nargout, octave_idx_type n_to_find, int direction) { // There are far fewer special cases to handle for a PermMatrix. octave_value_list retval ((nargout == 0 ? 1 : nargout), Matrix ()); octave_idx_type nc = v.cols (); octave_idx_type start_nc, count; // Determine the range to search. if (n_to_find < 0 || n_to_find >= nc) { start_nc = 0; n_to_find = nc; count = nc; } else if (direction > 0) { start_nc = 0; count = n_to_find; } else { start_nc = nc - n_to_find; count = n_to_find; } bool scalar_arg = (v.rows () == 1 && v.cols () == 1); Matrix idx (count, 1); Matrix i_idx (count, 1); Matrix j_idx (count, 1); // Every value is 1. Array<double> val (dim_vector (count, 1), 1.0); if (count > 0) { const octave_idx_type* p = v.data (); if (v.is_col_perm ()) { for (octave_idx_type k = 0; k < count; k++) { OCTAVE_QUIT; const octave_idx_type j = start_nc + k; const octave_idx_type i = p[j]; i_idx(k) = static_cast<double> (1+i); j_idx(k) = static_cast<double> (1+j); idx(k) = j * nc + i + 1; } } else { for (octave_idx_type k = 0; k < count; k++) { OCTAVE_QUIT; const octave_idx_type i = start_nc + k; const octave_idx_type j = p[i]; // Scatter into the index arrays according to // j adjusted by the start point. const octave_idx_type koff = j - start_nc; i_idx(koff) = static_cast<double> (1+i); j_idx(koff) = static_cast<double> (1+j); idx(koff) = j * nc + i + 1; } } } else if (scalar_arg) { // Same odd compatibility case as the other overrides. idx.resize (0, 0); i_idx.resize (0, 0); j_idx.resize (0, 0); val.resize (dim_vector (0, 0)); } switch (nargout) { case 0: case 1: retval(0) = idx; break; case 5: retval(4) = nc; // Fall through case 4: retval(3) = nc; // Fall through case 3: retval(2) = val; // Fall through! case 2: retval(1) = j_idx; retval(0) = i_idx; break; default: panic_impossible (); break; } return retval; } DEFUN (find, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {@var{idx} =} find (@var{x})\n\ @deftypefnx {Built-in Function} {@var{idx} =} find (@var{x}, @var{n})\n\ @deftypefnx {Built-in Function} {@var{idx} =} find (@var{x}, @var{n}, @var{direction})\n\ @deftypefnx {Built-in Function} {[i, j] =} find (@dots{})\n\ @deftypefnx {Built-in Function} {[i, j, v] =} find (@dots{})\n\ Return a vector of indices of nonzero elements of a matrix, as a row if\n\ @var{x} is a row vector or as a column otherwise. To obtain a single index\n\ for each matrix element, Octave pretends that the columns of a matrix form\n\ one long vector (like Fortran arrays are stored). For example:\n\ \n\ @example\n\ @group\n\ find (eye (2))\n\ @result{} [ 1; 4 ]\n\ @end group\n\ @end example\n\ \n\ If two outputs are requested, @code{find} returns the row and column\n\ indices of nonzero elements of a matrix. For example:\n\ \n\ @example\n\ @group\n\ [i, j] = find (2 * eye (2))\n\ @result{} i = [ 1; 2 ]\n\ @result{} j = [ 1; 2 ]\n\ @end group\n\ @end example\n\ \n\ If three outputs are requested, @code{find} also returns a vector\n\ containing the nonzero values. For example:\n\ \n\ @example\n\ @group\n\ [i, j, v] = find (3 * eye (2))\n\ @result{} i = [ 1; 2 ]\n\ @result{} j = [ 1; 2 ]\n\ @result{} v = [ 3; 3 ]\n\ @end group\n\ @end example\n\ \n\ If two inputs are given, @var{n} indicates the maximum number of\n\ elements to find from the beginning of the matrix or vector.\n\ \n\ If three inputs are given, @var{direction} should be one of\n\ @qcode{\"first\"} or @qcode{\"last\"}, requesting only the first or last\n\ @var{n} indices, respectively. However, the indices are always returned in\n\ ascending order.\n\ \n\ Note that this function is particularly useful for sparse matrices, as\n\ it extracts the non-zero elements as vectors, which can then be used to\n\ create the original matrix. For example:\n\ \n\ @example\n\ @group\n\ sz = size (a);\n\ [i, j, v] = find (a);\n\ b = sparse (i, j, v, sz(1), sz(2));\n\ @end group\n\ @end example\n\ @seealso{nonzeros}\n\ @end deftypefn") { octave_value_list retval; int nargin = args.length (); if (nargin > 3 || nargin < 1) { print_usage (); return retval; } // Setup the default options. octave_idx_type n_to_find = -1; if (nargin > 1) { double val = args(1).scalar_value (); if (error_state || (val < 0 || (! xisinf (val) && val != xround (val)))) { error ("find: N must be a non-negative integer"); return retval; } else if (! xisinf (val)) n_to_find = val; } // Direction to do the searching (1 == forward, -1 == reverse). int direction = 1; if (nargin > 2) { direction = 0; std::string s_arg = args(2).string_value (); if (! error_state) { if (s_arg == "first") direction = 1; else if (s_arg == "last") direction = -1; } if (direction == 0) { error ("find: DIRECTION must be \"first\" or \"last\""); return retval; } } octave_value arg = args(0); if (arg.is_bool_type ()) { if (arg.is_sparse_type ()) { SparseBoolMatrix v = arg.sparse_bool_matrix_value (); if (! error_state) retval = find_nonzero_elem_idx (v, nargout, n_to_find, direction); } else if (nargout <= 1 && n_to_find == -1 && direction == 1) { // This case is equivalent to extracting indices from a logical // matrix. Try to reuse the possibly cached index vector. retval(0) = arg.index_vector ().unmask (); } else { boolNDArray v = arg.bool_array_value (); if (! error_state) retval = find_nonzero_elem_idx (v, nargout, n_to_find, direction); } } else if (arg.is_integer_type ()) { #define DO_INT_BRANCH(INTT) \ else if (arg.is_ ## INTT ## _type ()) \ { \ INTT ## NDArray v = arg.INTT ## _array_value (); \ \ if (! error_state) \ retval = find_nonzero_elem_idx (v, nargout, \ n_to_find, direction);\ } if (false) ; DO_INT_BRANCH (int8) DO_INT_BRANCH (int16) DO_INT_BRANCH (int32) DO_INT_BRANCH (int64) DO_INT_BRANCH (uint8) DO_INT_BRANCH (uint16) DO_INT_BRANCH (uint32) DO_INT_BRANCH (uint64) else panic_impossible (); } else if (arg.is_sparse_type ()) { if (arg.is_real_type ()) { SparseMatrix v = arg.sparse_matrix_value (); if (! error_state) retval = find_nonzero_elem_idx (v, nargout, n_to_find, direction); } else if (arg.is_complex_type ()) { SparseComplexMatrix v = arg.sparse_complex_matrix_value (); if (! error_state) retval = find_nonzero_elem_idx (v, nargout, n_to_find, direction); } else gripe_wrong_type_arg ("find", arg); } else if (arg.is_perm_matrix ()) { PermMatrix P = arg.perm_matrix_value (); if (! error_state) retval = find_nonzero_elem_idx (P, nargout, n_to_find, direction); } else if (arg.is_string ()) { charNDArray chnda = arg.char_array_value (); if (! error_state) retval = find_nonzero_elem_idx (chnda, nargout, n_to_find, direction); } else if (arg.is_single_type ()) { if (arg.is_real_type ()) { FloatNDArray nda = arg.float_array_value (); if (! error_state) retval = find_nonzero_elem_idx (nda, nargout, n_to_find, direction); } else if (arg.is_complex_type ()) { FloatComplexNDArray cnda = arg.float_complex_array_value (); if (! error_state) retval = find_nonzero_elem_idx (cnda, nargout, n_to_find, direction); } } else if (arg.is_real_type ()) { NDArray nda = arg.array_value (); if (! error_state) retval = find_nonzero_elem_idx (nda, nargout, n_to_find, direction); } else if (arg.is_complex_type ()) { ComplexNDArray cnda = arg.complex_array_value (); if (! error_state) retval = find_nonzero_elem_idx (cnda, nargout, n_to_find, direction); } else gripe_wrong_type_arg ("find", arg); return retval; } /* %!assert (find (char ([0, 97])), 2) %!assert (find ([1, 0, 1, 0, 1]), [1, 3, 5]) %!assert (find ([1; 0; 3; 0; 1]), [1; 3; 5]) %!assert (find ([0, 0, 2; 0, 3, 0; -1, 0, 0]), [3; 5; 7]) %!test %! [i, j, v] = find ([0, 0, 2; 0, 3, 0; -1, 0, 0]); %! %! assert (i, [3; 2; 1]); %! assert (j, [1; 2; 3]); %! assert (v, [-1; 3; 2]); %!assert (find (single ([1, 0, 1, 0, 1])), [1, 3, 5]) %!assert (find (single ([1; 0; 3; 0; 1])), [1; 3; 5]) %!assert (find (single ([0, 0, 2; 0, 3, 0; -1, 0, 0])), [3; 5; 7]) %!test %! [i, j, v] = find (single ([0, 0, 2; 0, 3, 0; -1, 0, 0])); %! %! assert (i, [3; 2; 1]); %! assert (j, [1; 2; 3]); %! assert (v, single ([-1; 3; 2])); %!test %! pcol = [5 1 4 3 2]; %! P = eye (5) (:, pcol); %! [i, j, v] = find (P); %! [ifull, jfull, vfull] = find (full (P)); %! assert (i, ifull); %! assert (j, jfull); %! assert (all (v == 1)); %!test %! prow = [5 1 4 3 2]; %! P = eye (5) (prow, :); %! [i, j, v] = find (P); %! [ifull, jfull, vfull] = find (full (P)); %! assert (i, ifull); %! assert (j, jfull); %! assert (all (v == 1)); %!assert (find ([2 0 1 0 5 0], 1), 1) %!assert (find ([2 0 1 0 5 0], 2, "last"), [3, 5]) %!assert (find ([2 0 1 0 5 0], Inf), [1, 3, 5]) %!assert (find ([2 0 1 0 5 0], Inf, "last"), [1, 3, 5]) %!error find () */